The present invention relates to a sprayable skin composition which may be used to reinforce plastic products, and more particularly to a composition which may be applied by spraying without the formation of air bubbles.
Many plastic products, such as boat hulls, boat bulkheads, and tub and shower stalls, are reinforced with glass fibers to provide rigidity to the product. In a typical process, glass fibers are mixed with a synthetic resin and applied as a skin layer on a gel coated surface, typically in a mold, followed by the application of one or more bulk fiberglass layers. The resin is then cured, and the product is then removed from the mold for use. However, because the mixture of glass fibers and synthetic resin is a non-homogeneous mixture which is typically applied with a chopper gun or hand-laid over the gel coat, this process often results in the formation of air bubbles between the layer of gel coat and the skin layer of glass fibers/resin. While the air bubbles may be removed by a process in which the bubbles are rolled out, such as with the use of a handheld roller or paint brush, such a step adds additional time and expense to the manufacture of the product.
U.S. Pat. No. 4,568,604 describes a method which avoids the formation of small air bubbles or voids by applying a barrier layer of a synthetic resin and filler which is applied to the gel coat before the glass fiber material is applied. However, such a barrier layer functions primarily as a filler, and has a relatively long gel time.
Therefore, there remains a need in the art for an improved skin composition and method of applying it which does not require rolling out to remove air bubbles, which gels quickly, and which provides sufficient reinforcement properties to the finished product.